This invention relates to coordinate measuring machines having structure supporting a probe for movement relative to a workpiece to be measured and relative to a means for continually measuring the position of the probe relative to a datum, the probe having means for generating a signal when having a predetermined relationship with a proximate surface of the workpiece. In operation, the probe is moved toward a said surface and the signal is used to determine the output of the measuring means at the instant when the probe attains said predetermined relationship thereby to determine the position of said surface relative to said datum.
To speed up the measuring operations it is the practice to move the probe rapidly from one to the next of the surfaces to be measured. However, this practice is limited by dynamic deflection of the support structure. In other words, if, at the instant when said signal is generated, the probe is subject to acceleration or deceleration, the measurement is different from what it would be if the probe had a constant velocity. If this difference is greater than a given tolerance the measurement is useless. It is an object of this invention to overcome or reduce this difficulty.